One such hand propelled vehicle which is now commercially available is a hand propelled "desk dolly" which comprises a wheeled platform movable over the floor by hand, a frame of lightweight steel members disposed over, and mounted by, and covering a greater horizontal area than, the platform, and a mechanical jack by which the frame can be adjusted up and down relative to the platform. In use, the dolly is pushed into the space forming the bay beneath the desk, the frame is jacked up to lift the desk off the floor, and the desk is then transported by rolling the dolly over the floor. The "desk" dolly just described has the disadvantage of lack of versatility in that the large areal size of its frame and the fact that it cannot be lowered below the platform makes it unsuitable for the lifting of many loads.
Another such hand propelled vehicle is a hand truck having a pair of swivelable wheels at its bottom and having thereon an outwardly projecting lifting shoe which, when the truck is mostly upright, is at the truck's bottom and is shiftable between fully lowered and raised positions by a hydraulic jack on the truck. To lift a heavy load seated on the floor, two of such trucks are brought to opposite sides of the load to insert their respective shoes under it, the hydraulic jacks of both trucks are then operated to shift their respective shoes simultaneously from their lowered positions to raised positions at which time the shoes are held to thereby lift and hold the load off the floor, and the two trucks are then tied together by flexible fabric belts to form with the load an assemblage which is movable over the floor to transport the load. A disadvantage of the arrangement just described is that the hydraulic jacks which are on the hand trucks are expensive. Further, two men are needed to lift the load simultaneously. Still further, because, after the load has been lifted, the two trucks are coupled together only by fabric belts, the resulting assemblage is at best a jury rig which provides support for the load which is less stable than a rigid support platform would provide and which, moreover, may be difficult to roll over the floor since all the wheels on the two trucks are swivelable.